The present invention concerns a process for the production of a structure of colour filter layer system regions where:
a coating layer structure with coated surface regions and coating-free regions is produced on a substrate; PA1 a colour filter layer system is deposited on the coating layer structure; PA1 the coated surface regions with the overlying colour filter layer system regions are removed.
Such a production system is known as the lift-off process. It is used for example to produce red-green-blue colour filter layer system structures, in particular for LCD or CCD production. The colour filter layer systems can structured by pixel structuring or strip structuring.
Often in such systems, between the colour filter layer system regions is applied an opaque layer of material, usually chromium, which covers the filter layer system transitions and is usually known as the black matrix structure.
In general the said lift-off technology is advantageous from the point of view of commercial production as relatively few process stages are necessary in a vacuum. In relation to this technology, reference is made to US-A-3 914 464 or DE-30 13 142. It is also known to produce metallic layer structures using the lift-off technique in semiconductor production for example. Such metallic layer structures, for example approximately 1 .mu.m thick, can be removed like a foil during lift-off without disintegrating. In this latter technique it is therefore necessary to produce the lift-off coating structure such that its side surfaces overhang. This ensures that the metal coating regions deposited on the coating-free regions are not also removed during the lift-off process. Overhanging coating structures can however only remain as such if the subsequent coating with the said metal coating is applied almost vertically to the base or substrate surface. When the coating structure is then dissolved during the lift-off process, the metal layer to be removed remains as a cohesive structure and during removal very few particles are produced which can be deposited on the remaining layer structures applied to the coating-free regions.
In this respect the lift-off process behaves totally differently on dielectric or generally brittle filter layer systems: on the one hand the overhanging coating layer structures can be omitted as the said filter layer systems are brittle and cannot be removed as a skin. They crumble into multiple small flakes during the lift-off process. At the structure edges, automatic layer system break points occur. The flakes can be deposited on the remaining structure where they frequently land, i.e. due to molecular forces they become attached to the surface of the remaining structure and are very difficult to remove, which can often cause damage to the filter layer system structure, for example the red-green-blue filter structure (RGB).